Rails Generators

osx 10.10.1 | Jan 15, 2015 ###Quick reference to Rails Generators.

##Migrations What has been generated for you is just a starting point. You can add or remove from it as you see fit by editing the migration file.

###Creating Tables If the migration name is of the form "CreateXXX" and is followed by a list of column names and types then a migration creating the table XXX with the columns listed will be generated. For example: bin/rails generate migration CreateProducts name:string part_number:string generates:

class CreateProducts < ActiveRecord::Migration
  def change
    create_table :products do |t|
      t.string :name
      t.string :part_number
    end
  end
end

###Changing / Modifing Tables

####Adding Columns Generate an empty but corectly named migration file:
bin/rails generate migration AddPartNumberToProducts

Include a list of column names and types:
bin/rails generate migration AddPartNumberToProducts part_number:string

will generate:

class AddPartNumberToProducts < ActiveRecord::Migration
  def change
    add_column :products, :part_number, :string
  end
end

Optionaly add an index on the new column, you can do that as well: bin/rails generate migration AddPartNumberToProducts part_number:string:index will generate:

class AddPartNumberToProducts < ActiveRecord::Migration
  def change
    add_column :products, :part_number, :string
    add_index :products, :part_number
  end
end

####Removing Columns Generate a migration for removing a column: bin/rails generate migration RemovePartNumberFromProducts part_number:string generates:

class RemovePartNumberFromProducts < ActiveRecord::Migration
  def change
    remove_column :products, :part_number, :string
  end
end

##Models Capitolize and Singular model name.

bin/rails generate model Article title:string text:text

Now with an assosiation. Notice the article:references.

bin/rails generate model Comment commenter:string body:text article:references

Generates:

• Migration file (To create the corresponding database table.)
• Model file (The Comment model with the belongs_to :article line.)
• Corisponding Test file

##Controllers